The hard carbon (HC) anode materials demonstrate high capacity and excellent rate performance in lithium-ion batteries. However, HC anodes suffer from excessive loss of Li+ ions during the formation of the solid electrolyte interphase (SEI) film, leading to poor cycling stability, which hinders their large-scale applications. Herein, a facile pre-lithiation strategy is proposed to achieve multi-functional precompensation of carbon nanofibers (CNFs) anodes. Both experimental and density functional theory (DFT) calculation results revealed that the strategy compensated for the loss of Li+ ions and reacted with four structures of CNFs during pre-lithiation, including tiny graphite domains, CO-containing functional groups, defects, and micropores. Furthermore, the lithium in pre-lithiated carbon nanofibers (pCNFs) existed in various forms, consisting of LiC24 and LiC18, Li─O─C, quasi-metallic lithium, and Li+ ions. Moreover, the uniformly distributed lithium on the surface of pCNFs induced the formation of denser and more robust LiF/Li2CO3-rich SEI film, which promoted Li+ ions transport. As a result, pCNFs showed more stable cycling performance (369.8mAhg-1, almost no decay for 1500 cycles). This work provides deeper insight into chemical pre-lithiation and offers a simple and mild strategy for highly stable batteries.
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